Solid state illumination for endoscopy

ABSTRACT

Various embodiments for providing solid state illumination for endoscopy or borescopy are provided. Generally, various medical or industrial devices can include one or more solid state or other compact electro-optic illuminating devices located thereon. The solid state or compact electro-optic illuminating device can include, but is not limited to, a light emitting diode (LED), laser diode (LD), or other Infrared (IR) or Ultraviolet (UV) source. Solid state sources of various wavelengths may be used to illuminate an object for imaging or detecting purpose or otherwise conditioning purpose. The solid state illuminating device may be placed on the exterior surface of the device, inside the device, deployably coupled to the distal end of the device, or otherwise disposed on the device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims benefit of and priority to U.S. ProvisionalPatent Application Ser. No. 60/612,889 filed Sep. 24, 2004 and entitled“Solid State Illumination for Endoscopy,” which application is hereinincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

The present invention relates generally to apparatus for theillumination of endoscopic and borescopic fields, in minimally invasivesurgical (MIS) procedures, general or diagnostic medical or industrialprocedures using endoscopes or borescopes, respectively. Moreparticularly, embodiments of the invention relate to use of LightEmitting Photodiode and other solid state light sources in endoscopicand borescopic procedures, as a means of illumination.

2. The Relevant Technology

Laparoscopy is used in both diagnostic and surgical procedures.Currently, MIS procedures, as opposed to open surgical procedures, areroutinely done in almost all hospitals. Minimally invasive techniquesminimize trauma to the patient by eliminating the need to make largeincisions. This both reduces the risk of infection and reduces thepatient's hospital stay. Laparoscopic and endoscopic procedures in MISuse different types of endoscopes as imaging means, giving the surgeonan inside-the-body view of the surgical site. Specialized endoscopes arenamed depending on where they are intended to look. Examples include:cystoscope (bladder), nephroscope (kidney), bronchoscope (bronchi),laryngoscope (larynx+the voice box), otoscope (ear), arthroscope(joint), laparoscope (abdomen), gastrointestinal endoscopes, andspecialized stereo endoscopes used as laparoscopes or for endoscopiccardiac surgery.

The endoscope may be inserted through a tiny surgical incision to viewjoints or organs in the chest or abdominal cavity. More often, theendoscope is inserted into a natural body orifice such as the nose,mouth, anus, bladder or vagina. There are three basic types ofendoscopes: rigid, semi-rigid, and flexible. The rigid endoscope comesin a variety of diameters and lengths depending on the requirements ofthe procedure. Typical endoscopic procedures require a large amount ofequipment. The main equipment used in conjunction to the visual part ofthe endoscopic surgery are the endoscope body, fiber optics illuminationbundles, illumination light source, light source controller, imagingcamera, camera control module, and video display unit.

The laparoscope is a rigid endoscope as illustrated in FIG. 1. It allowsfor visualization of the abdominopelvic cavities for diagnostic orsurgical techniques. The laparoscope is inserted into the peritonealcavity via a cannula that runs through the abdominal wall. There aremany different features of laparoscopes, such as the size and field ofvision, which determine the effectiveness of the instrument.

As illustrated in FIG. 1, the basic laparoscope is made up of a longthin tube 101 with an eyepiece 103 at one end for viewing into thepatient. Fiber optic light introduced to the endoscope at fiber port102, and launched into fiber optics 123 (FIG. 3), passes through theendoscope body 101, illuminating the area 124 that is being observed, asillustrated by radiation pattern 125 in FIG. 3. Laparoscopes arecharacterized by diameter and the direction of view. The direction ofview is the angle 107 between the axis of the laparoscope 105 and thecenter field of view 106, as illustrated in FIG. 1. Typical endoscopeshave lengths of approximately 30 cm and diameters in the range of 4 to10 mm. Laparoscopes consist of two important lenses, the ocular lens atthe eyepiece and the objective lens 122 at the distal end of theendoscope 101 in FIG. 3. Other lens sets acting as relay lenses 121 inFIG. 3, are used in-between the objective lens and the eye piece or theCCD camera or image position 127. Imaging rays 126 traverse the lengthof the scope through all the imaging optics.

The rigid endoscope also comes in different viewing angles: 120 degreeor retrograde, for viewing backward; 90 degree and 70 degree for lateralviewing; 30 degree (104 as illustrated in FIG. 1) and 45 degree forforward oblique views; and 0 degree for forward viewing. The angle ofthe objective lens 122 used is determined by the position of thestructure to be viewed.

Other surgical instruments and tools are also inserted into the body,for the operation and specific surgical manipulation by the surgeon. Theinsertion is done through open tubes provided inside the endoscope bodyfor instrument insertion, such as in gastrointestinal endoscopes, orthrough separate incisions in the abdominal or chest wall 113, usingcannula 110 (straight or curved stainless steel or plastic tubes whichare inserted into a small opening or incision in the skin as illustratedin FIG. 2). The cannula opening at the proximal end 112 outside the bodyis used to guide different instruments inside the body, where they areexposed to the inside of body at the distal end 111 of the cannula (FIG.2). Cannulas can make a seal at the incision site 114.

In a typical gastrointestinal endoscope, a tool opening is provided atthe distal end of the scope, where inserted medical instruments gainaccess to the body following the scope body.

Endoscopes can be diagnostic, for observation only, or operative, havingchannels for irrigation, suction, and the insertion of accessoryinstruments when a surgical procedure is planned. Thus, endoscope bodiesalso could provide mechanical or electrical control sections, buttonsfor valves such as a suction valve, a CO2 valve, a water bottleconnector, a water feed, a suction port, etc. The common component thatall endoscopes must be equipped with is a light guide section forillumination.

An illustration showing typical endoscope optics is shown in FIG. 3.Common imaging sections of the endoscope are an ocular or eyepiece,relay lenses (in the case of rigid scopes), a flexible imagingfiber-optic bundle (in the case of flexible scopes), and an objectivelens system. Endoscopes are either used as stand alone units, with thesurgeon looking into the scope from the ocular or eye piece of theendoscope, or in conjunction with digital cameras, where an image of thesurgical site is incident on the image capture device (charge coupleddevice or CCD) of the camera. Using a display device, the surgeonperforms the operation looking at the image on the video monitor.

With recent technology improvements in the field of electronic imagingreducing the size of the image capture device (CCD), some endoscopesused in MIS and diagnostic procedures are equipped with a highresolution distal end camera system, commonly referred to as Chip on aStick, one example of which is illustrated in FIG. 4. These flexibleendoscopes use a CCD chip 137 at the distal end of the endoscopedirectly capturing the image through the objective lens 131, in whichcase the flexible part (132) of the endoscope body, contains only powerand communication wires for the CCD camera at the distal tip, ratherthan imaging optics 133 which is located in the rigid portion 131 of theendoscope. Light guides 138 are still necessary for this type ofelectronic scope to provide adequate lighting (134) of the surgical site136 for imaging purposes.

Other, more complicated MIS systems make use of robotic surgical toolsand instruments, and/or provide stereoscopic images of the surgical sitefor the surgeon, improving the surgeon's dexterity, precision and speedof operation. In these more sophisticated MIS imaging applications morespecific types of illumination systems or multiple illuminators areused.

Endoscopes can have a variety of forms, ranging in diameter, tubelength, and angle of view. However, all types of endoscopes commonly useoptical fibers to illuminate the surgical site. Illumination is a veryimportant part of laparoscopy because there is no light source insidethe body. Fiber optic cold light is used to project light down thelaparoscope from an external source. Large lamps with broadband outputare used to couple light into the illumination light guides, where lightguides transfer the illumination light from the light source to theillumination fiber bundle inside the endoscope body. A typical scopeattached to an illumination light guide is shown in FIG. 1. One or morelight guide bundles are used to couple light into the endoscopeillumination fiber bundles.

The use of fiber bundles inside the endoscope body or tube occupiesspace that otherwise could have been used by the imaging optics. Thiscan be seen in FIG. 3, showing the fiber optic illuminators sharing theendoscope body with the imaging optics. Limitations on the optical lensterrain diameter, as well as the imaging fiber bundle thickness,correlate directly to the imaging resolution vs. size of the image. Thelarger the lens diameter or imaging bundle thickness, the better theresolution of the endoscope for a certain field of view (FOV) or imagesize. This is the main reason that larger diameter scopes are consideredbetter in optical quality than narrower scopes. However, large scopediameters are not desirable for certain operations where space islimited on the operation site.

Different illumination fiber geometries are used to reduce the spaceconstraint inside the scope body. For this reason, and to have a moreuniform illumination, the imaging fiber bundles are also split in somecases to have two or more points of illumination at the distal end ofthe scope. In other types of scopes, illumination is made into acircular ring pattern at least at the distal end of the endoscope,similar to the ring illumination of microscopy.

The light source for the endoscope is either a xenon bulb, which createsa high intensity white light suitable for smaller-diameter endoscopes, ahalogen bulb, which creates a yellowish light suitable for generalendoscopic work, or a Metal Halide lamp. Since most broadband lightsources also produce large amounts of Infrared Red (IR) wavelengthlight, IR cut filters and lamp dichroic reflectors (heat blockingfilters and reflectors that reduce the radiation usually associated withheat production) are used in the illumination light source to preventthe transfer of IR radiation to the body. Thus, broadband visible coldlight is highly desirable in laparoscopic procedures providing decreasedthermal injury to tissues. Since most CCD cameras are also sensitive toIR radiation (due to Silicon absorption spectrum), extra IR cut filtersare used in front of the camera to prevent glare caused by IR radiationin the camera.

Despite the precautions used in reducing the IR radiation, in actualitysome amount of infrared radiation in addition to the visible lightenters the fiber optic cable, and is transmitted through the cable andscopes into the body. When the light leaves the endoscope tip, the levelof infrared radiation has usually been reduced to a safe level throughabsorption by the optical fibers in the endoscope, and substantiallosses at the cable connections. However, if the cable is not connectedto the endoscope, the infrared output is not reduced sufficiently andeven could have the capability of igniting some materials if the cableis left at close proximity to absorbing combustible material. Thishazard exists in fiber illumination cables with high intensity lightsources.

Additionally, higher outputs not only increase the risk of fire, but mayintroduce the risk of burns during close-range inspection of tissue withthe endoscopes. Absorption of high-intensity radiation at visible lightwavelengths may also cause tissue heating, where additional filtering ofinfrared wavelengths may not eliminate this hazard. Furthermore, withthe increasing use of television systems with video cameras connected tothe endoscopes, many physicians operate light sources at their maximumintensities and believe they need even greater light intensities tocompensate for inadequate illumination at peripheral areas of the imagewhere the illumination intensity falls rather rapidly using today'sstandard illumination fiber guides.

Typical light sources are also deficient in their flux and colormanagement of their spectral output. A typical lamp spectral outputrequires time to come to an acceptable level during the warm-upprocedure, both in terms of lumens output as well as color quality orwhite point on the color gamut. The color temperature of the lamp basedilluminators, are typically deficient in producing the desirable colortemperature (daylight color temperature of 5600 Kelvin) for typicalendoscopic procedure. Color content of the lamp output also typicallyshifts during the life time of the lamp. Thus it is usually required toperform a white color balance adjustment in the camera controller eachtime an endoscope is used subsequent to the light source warm-upprocedure to obtain realistic color image. A repeat of the white colorbalance adjustment may also be necessary if the lamp intensity isadjusted through a large range.

Typical high power lamps also have very limited life time, measured inhours (Typically 50, 500, or 1000 hours for Halogen, Xenon or MetalHalide depending on the lamp), where the light output of the lampdegrades to about one half of its original light output. Typical lampmanufacturers typically do not specify or have a failure criteria basedon the color quality for the lifetime of the lamp.

Complicated and bulky optical schemes are incorporated in the lightguide optical sources for effective coupling of the light into theillumination fiber bundles. Special non-imaging optics such as glassrods, and lens elements are used to also uniformly couple light into allthe fibers inside the illumination fiber bundle. All these increase thecost and also size of having high brightness, uniform fiber opticillumination light sources. Typical high brightness light sources alsoincorporate powerful fans to dissipate the large amount of heatgenerated inside the light source package. In fact in a typicalendoscopic procedure, light sources are one of the main sources of heatgeneration and the associated fans on the light sources are one of themain sources of noise in the surgical environment. Large package size ofhigh power lamps also add extra burden to the premium space in adiagnostic and surgical environment.

Light sources normally give off electromagnetic interference (EMI),where the starting pulses from the lamp could reset or otherwiseinterfere with other digital electronics devices in today's surgicalenvironment.

In an operating environment, the light source(s) are placed at adistance, on a table top or rack, mounted away from the patient and theendoscope. Fiber optic light bundles to transfer the light from thelight source to the endoscope are used as light links between the lightsource and the endoscope. These fiber bundles are not only bulky andexpensive, but their price increases by the length of the fiber bundle,whereas the amount of light transmitted goes down as the length of thefiber bundle increases. To conveniently place the light source and fiberbundle away from the operational site, longer fiber bundles arenecessary, however the attenuation, or drop in the transmitted opticalflux increases with the length of the fiber used as well, requiring morepowerful light sources.

Use of fiber optic light guides as a means of transfer of illuminationlight from the proximal to the distal end of the endoscope alsoincreases the chance of relative light loss. The relative opticallight-loss measurement quantifies the degree of light loss from thelight source to the distal tip of the endoscope. The relative light losswill increase with fiber-optic damage. Extra heat will also be generatedin the broken fiber ends inside the endoscope. In fact the major failuremode for the fiber optic bundles delivering the light to the endoscope,and the optical system inside the endoscope is breakage of the fibers.

As illustrated in FIG. 1, the illumination fiber bundle(s) 102 commonlyjoin the endoscope body at some angle near the ocular (103) at theproximal side of the endoscope. The fiber guide body and the mainendoscope body are commonly joined together in a welding process atjoint 108 illustrated in FIG. 1. The construction and design of thiswelded joint is often a weakness in the endoscope manufacturing and use,where after many operations, high temperature and high humiditysterilizations, and successive handling, this welded joint could getdamaged and break, exposing the internal parts of the scope to theenvironment when the seal is broken.

Color CCD cameras use alternate color dies on the individual CCD pixels,to capture color images. Green and red, and green and blue pixels arealternated in rows. This spatial color sampling limits the colorresolution of the color CCD cameras, since each pixel is dedicated tocapturing a single color in the color image.

3 chip CCD cameras (red CCD chip, blue CCD chip, and green CCD chip) arealso used in high resolution applications, where all the pixels in eachCCD are dedicated to detecting the single color content of the image.The individual color captured images from the 3 CCDs are then puttogether electronically, as the multi-color image is reproduced on theviewing display. Three chip CCD cameras are expensive and bulky.

BRIEF DESCRIPTION OF THE DRAWINGS

To further clarify the above and features of the present invention, amore particular description of the invention will be rendered byreference to specific embodiments thereof which are illustrated in theappended drawings. It is appreciated that these drawings depict onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope. The invention will be described andexplained with additional specificity and detail through the use of theaccompanying drawings in which:

FIG. 1 illustrates a typical angled endoscope, with fiber optic lightport for illumination, and an eye piece for viewing;

FIG. 2 illustrates a cannula inserted into the body cavity.

FIG. 3 illustrates the cross section of a typical zero degree, rigidendoscope with associated terrain for relay of the image through thelength of the endoscope;

FIG. 4 illustrates the cross section of a zero degree typical flexibleendoscope body (Chip on the Stick) with fiber optics illumination;

FIGS. 5 a to 5 d illustrate various single LED sources, without and withvarious encapsulation optics;

FIGS. 6 a and 6 b illustrate a self lighted cannula using multiple LEDsources installed at the proximal end of the cannula;

FIG. 7 illustrates a cannula body used as the illuminator for inside thebody cavity;

FIG. 8 illustrates a cannula with built in LED illuminators at thedistal end of the cannula;

FIGS. 9 a and 9 b illustrate an angled endoscope with modified distaltip, incorporating an array of LEDs for illumination of the surgicalsite;

FIG. 10 illustrates fixed solid state illuminators assembled behind thefirst negative lens of the endoscope, used as window at the distal endof a flexible endoscope;

FIGS. 11 a and 11 b illustrate inclusion of the LED sources within theobjective lens of an endoscope, using a beam splitter;

FIGS. 12 a and 12 b illustrate insertion and deployment of a flexiblemembrane with built in LED illuminators, to light the surgical areainside the body;

FIGS. 13 a and 13 b illustrate possible deployment of LED illuminatorsat the distal end of a flexible endoscope;

FIGS. 14 a and 14 b illustrate possible deployment of LED illuminatorsstored within the objective lens of a flexible endoscope;

FIGS. 15 a and 15 b illustrate possible deployment of LED illuminatorsstored next to the objective lens of a rigid body endoscope;

FIGS. 16 a and 16 b illustrate possible deployment of LED illuminatorsstored along the distal tip of a rigid body endoscope;

FIGS. 17 a, 17 b, and 17 c illustrate LED illuminators built into thebody of a surgical instrument or tool, with possible deployment duringoperation to illuminate the surgical site.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of the invention concern monochromatic orpolychromatic solid state light sources such as high power LightEmitting Devices (LEDs) and Laser Diodes as a means of illumination in adiagnostic or surgical endoscopic procedures, or functional borescopicsystems. In particular, these solid state light sources are incorporatedat the distal end of the endoscope, borescope, surgical or industrialtools, and the tip end of cannulas and other functional devices. Theycan also be incorporated in an illumination body that is insertedseparately, or in conjunction with a lighted or dark scope, into thebody. The illumination of an object inside a body, a body herein beingdefined as at least a portion of a human, animal or physical object noteasily accessible, is performed to detect the modified light, image theobject, or manipulate a change in the object. The solid stateillumination schemes of the present invention can replace, or can beused in addition to, the conventional fiber optic illumination systemand other diagnostic devices such as ultrasound imaging used inendoscopy and borescopy.

Use of such solid state sources inside a cavity in the body, replacesvariety of instruments otherwise needed for the same purpose, such as anexternal light source, fiber light guides, and means of transmitting thelight to the desired object.

Exemplarily, the use of LED sources has several advantages over theconventional external white light source. With an LED basedillumination, a true, visible light source with no IR content isavailable for the endoscopic application. Therefore, the complicated IRmanagement of the light source is eliminated. There is no longer a firehazard associated with light guides that may be left on, and no heatmanagement inside the scope is needed.

LEDs can provide light at any region of the visible spectrum. Red,Green, and Blue LEDs in primary colors can be used together to form awhite illumination, Phosphor-converted LEDs can provide white outputdirectly without any color mixing, Infra Red (IR) or Ultraviolet (UV)LEDs can be used for their special characteristic in light transmissionin the medium of insertion or the effect they have on the object ofinterest.

LED lifetimes are more than order of magnitude longer than bulb typelight sources (50k hours depending on the drive condition). The longlife time in conjunction with the reliability associated with solidstate lighting practically illuminates any lamp outages in an MISprocedure, where dependable illumination is one of the most criticalparts of the system. In fact LED life time is more in line with theusage life time of most MIS surgical tools.

LED power consumption is also much lower than high power light sources.The LED illumination system is most efficient since there is no need fori) transferring light from the source through fiber optic light guides,ii) coupling the light into the scope light guides, or iii) transmittingthrough the fiber optic light guides through bends in the fiber. Lightpowers in the order of 1000 lumens are in fact possible with use of fewhigh power LEDs.

Further, LEDs are robust, and do not break, unlike fiber optic lightguides. Properly encapsulated LEDs, can withstand severe environmentalconditions and cleaning procedures.

LEDs do not produce any electromagnetic interference, thus eliminatingthe need for complicated EMI management system such as Faraday caging.Because of size, reliability and safety of LEDs, these light sources areideal choice for “in location” illumination of the object inside thebody. Where only electrical power is transmitted to the light sourceinside the body along with possible electrical control signals.

By eliminating conventional fiber optic illumination guides inside theendoscope body, there is more space for the imaging optics or imagingfibers, where the size directly relates to the image informationtransfer capability of the system. With more space available to theimaging optics, larger diameter optics and imaging fiber diameters canbe used, making larger image FOVs and higher resolution possible.

LEDs do not require a warm-up procedure. LEDs are capable of providinginstant illumination with the exact color point at initiation. Opticalpower and color maintenance over the life time of the LED are alsocritical features of solid state light sources.

By using three color LEDs (red, green and blue) and synchronizing ablack and white camera system to grab the three synchronized colorcomponent images, the use of color camera chips or the high resolution 3CCD chip cameras is eliminated. Since a single CCD camera is used tocapture the three images in a time synchronized fashion, each colorcomponent image takes advantage of the full CCD image resolution byincorporating all the pixels in each color image component. Two examplesof exemplary embodiments of endoscopes having LED illuminators and CCDimage cameras are shown in FIG. 4. Simple black and white CCD or CMOScamera chips are also cheaper to use, especially compared to a 3 chipCCD camera, where in effect the resolution of the synchronized black andwhite imaging CCD using synchronized color illumination provided by theLEDs is equivalent to a same pixel 3 CCD chip camera.

Using the color synchronized image capture device also allows the use ofmuch higher resolution image capture devices in chip on the stickcameras where space is limited at the distal tip of the endoscope forthe image capture CCD. A variety of illumination configurations arepossible using LED chips, where the uniformity, angle and extent of theillumination are freely controlled by the positioning and design of theLED light sources.

FIGS. 5 a through 5 d illustrate various configurations of LED output.FIG. 5 a depicts a LED 140 disposed on a base 141. The LED 140 isunencapsulated resulting in output in the form of a Lambertian lightsource. This makes these solid state light sources ideal for endoscopicillumination applications where wide angular field of view needs to beproperly illuminated.

A simple lensing element can also be used in the form of an LEDencapsulant, where depending on the shape of the lens surface and thelens' distance from the LED surface, different angular illuminations orfocusing of the light can be easily accomplished. FIG. 5 b illustrates asimple lens encapsulation 143 maintaining the same Lambertian lightoutput as the unencapsulated LED, however with much higher lightextraction from the LED chip.

FIG. 5 c depicts an alternate surface structure for the LEDencapsulation, such as fresnel lens profile 144, diffractive optics orother refractive profiles can yield different angular extent of theencapsulated LED radiation pattern 144.

FIG. 5 d illustrates a simple lens encapsulation where higher indexencapsulation material is used in conjunction with positioning the lenssurface farther away than the lens radius of curvature resulting in asubstantial decrease in the angular extent of the radiation pattern 146can be achieved.

With controllable illumination color available to 3 color LEDs, thecolor gamut of the illumination can be changed according to theapplication using the drive condition for the independent color LEDs.This is highly desirable where the information content of the surgicalsite is mainly in a certain color, and where shifting the illuminationcolor can increase the visibility and differentiation needed indiagnostic evaluation of the surgical scene.

Using more illumination sources with other wavelengths than the threeprimary illumination colors, and matching the image detection framecapture sequence to that of the synchronized color illumination sources,allows higher quality image capture in terms of more realistic colors.Using only primary RGB colors the detected image color content is withinthe color triangle in the CIE color diagram. Adding LEDs with othercolors such as amber, cyan, and magenta, increases the detected colorgamut of the image substantially. With the recent color displays such asflat panel LCD displays using more than just primary color illuminators(such as with 6 LED back light illuminators), it is in fact possible topresent a “true color” image to the operator that was never beforepossible with the 3 color LED CCD cameras. This can be important incertain surgical applications where the color reproduction integrityplays an important role in the surgeon's perception of the scene ordiagnosis of the object.

LED illumination systems are modular, where one or multiple illuminationsystems can be inserted into the body independent of one another, viaseparate illumination bodies, at the distal end of an endoscope, orincorporated at convenient and efficient locations on surgical tool tipsor cannulas.

Different solid state light sources or combination of these sources canbe used to perform diagnostic as well as surgical or other functions ona body. A variety of illuminators can work in conjunction with oneanother and other devices to image, detect or modify the object.

One example of an embodiment of an LED illuminator 150 according to thepresent invention used in a cannula is illustrated in FIGS. 6 a and 6 b.In this exemplary embodiment, the body of the cannula which is clear tothe light in the visible spectrum is completely lit by white or colorLEDs 151 mounted at the proximal end 112 of the cannula. Electricalpower to the LEDs is provided by power connection 152. As illustrated inFIG. 6 b, the LED light fed into the cannula body goes through TotalInternal Reflection as it travels the length of the cannula to thedistal end 111, at which point the light leaves the cannula illuminatingthe surgical site and tools as indicated by radiation pattern 154.

In an alternative embodiment if a cannula 160 depicted in FIG. 7, thecannula body includes near its distal end 111 surface mount white orcolor LEDs 161. A cone type reflective cover (not shown) for these LEDs161 can also be inserted along with the cannula 160 into the body, wherethe LED light from the body of the cannula is directed more towards thedistal end of the cannula.

FIG. 8 illustrates another simple embodiment of a cannula 170 with whiteor color LEDs 171 mounted directly at the distal end 111 of the cannula170.

As depicted in FIGS. 9 a and 9 b, in an exemplary embodiment of an LEDilluminated endoscope 180, an array of white or color LED illuminators181 is built into an extension portion 181 a extending from the distaltip of an angled endoscope tube 101. The array of LEDs 181 can beencapsulated with lens elements 182 to establish the desiredillumination field and uniformity 184. FIG. 9 a illustrates thisexemplary embodiment of endoscope 101 in the side view, and FIG. 9 b isand end view illustration of such embodiment. Clear imaging port isnoted as 183 on these figures, and the LEDs are encapsulated using aFresnel type lens structure 182. Other tool insertion ports, multipleimaging ports for stereo imaging, or imaging ports with various Field ofView (FOV), can be used in the clear area of the distal end of theendoscope. Other solid state light sources such as laser diodes orvarious wavelength LEDs can be mounted in the vicinity of the LEDsources depicted in this embodiment to perform other functions using thesame device. Other forms of optics or optical elements such as lenses,polarizers and wave-plates can also be used in front of the illuminatorsor detection ports to modify the illumination extent or for properdetection of the light.

In another embodiment of a solid state illumination within an endoscope190, FIG. 10 illustrates the incorporation of white, color LEDs orlasers, IR or UV solid state light sources 191 behind the first negativelens 193 of the objective lens. This portion of the objective lens ineffect acts as a window for the illumination source 191, since theconcave portion of the first negative lens of the objective, istypically much smaller than the distal window of the scope. Solid stateillumination sources in this configuration can be directly mounted tothis glass window around the concave area of the lens. As theillumination light leaves the glass at the distal end, the angularradiation pattern 192 of the light expands as illumination is emittedoutside the glass. Refractive, polarization, or wave-plates can also beimplemented in the area of the negative lens beyond the concave portionto modify the illumination characteristic.

In yet another embodiment of LED illumination within the endoscope 200,white or combination of RGB LEDs can be used within the objective lens.As illustrated in FIG. 11 a, LEDs 201 can be mounted so that theillumination crosses the endoscope axis where the illumination lightfrom the LEDs is combined into the imaging path using beam splitteroptics 202.

FIG. 11 b illustrates an alternative positioning of the LED 203 withinthe objective lens in LED illuminated endoscope 200, without the use ofa beam splitter. Light emitted by the LEDs in this geometry pass throughthe distal portion of the objective lens, illuminating the surgical sitethrough the same window as the endoscope imaging optics.

LEDs provide a desirable cost advantage over conventional lamp and fiberguide systems, as it replaces the expensive light sources, long fiberoptic light guides to transfer light from the light source to the scope,and the illumination light guides inside the scope as well. Low levelpower is only needed for the LED light sources, thus the electricalconnection of the LEDs is much easier.

Only electrical power and LED control signals need to be provided forthe endoscope, eliminating the heavy and bulky fiber optics illuminationcable connection to the scope, increasing the maneuverability of theendoscope. LED illumination systems are also more robust to shock andvibrations or extreme environmental conditions than fiber opticillumination systems.

Since any heat generated from the LEDs is not in the form of radiativeheat, as in the case of lamps, it can be easily conducted out of theendoscope, or instrument tip using a conductive layer or the endoscopeor instrument body itself. Some of this heat can in fact be conductedtowards the endoscope optical window, such as in the embodiment of FIG.10 which shows endoscope 190, where the LEDs 191 are at intimate contactwith the endoscope window and its holder, which provides the propertemperature setting to avoid any condensation on the optical windowduring operation and additionally warms the end of the cold endoscopewhen it is inserted into the warm and humid body cavity. In turn aseparate low power infrared LED can also be used for the purpose ofheating the endoscope tip.

In addition to the above exemplary embodiments 180, 190 and 200, wherethe LED illuminators are used in fixed positions within the endoscopebody, other deployable embodiments are possible for effectiveillumination of the surgical site. In these deployable embodiments, theLED illuminators are deployable from an insertion position in which theyare held within the insertion body or within a close profile of theinsertion body, to an operational position where they are convenientlypointed to the object of interest. In operational position, theillumination light can be directed to the surgical site from beyond theendoscope body, where deployment of the LED holder structure positionsthe illuminators off axis from the imaging axis, possibly increasing thecollection efficiency of the imaging optics.

In some exemplary embodiments, this deployment can be accomplishedusing, by way of example and not limitation, an umbrella type deploymentstructure capable of being opened and closed by an operator. Differentvariations of this umbrella structure can be used depending on thedesired application, amount of illumination, and light positioningrequirement. FIG. 12 a illustrates one example of an umbrella-typedeployment structure where an LED-supporting structure is deployedthrough a cannula. A circular flexible membrane 181 is populated withwhite or color LEDs 182. This populated membrane 181 includes a springat its peripheral section (circular edge) of the membrane body. Themembrane 181 is deployably coupled to the distal end of the cannula. Inthe insertion position, the membrane is collapsed into a tube form 181a. Once the collapsed membrane 181 a is maneuvered to the desiredlocation, the membrane is fully deployed until it is outside the distalend 111 of the cannula. The spring action at the membrane's edge forcesthe membrane to open into a flat surface 181 b. LEDs 182 illuminate thesurgical site or other tools and instruments inserted into the body.

FIGS. 13 a and 13 b illustrate another embodiment of dynamic deploymentof LED illuminators. In FIG. 13 a LED illuminators 210 a in their “off”or insertion position. In order to deploy LEDs 210 a, the illuminators210 are flipped over the endoscope tip. Once the illuminator 210 b isdeployed (“on” position) the 210 b LEDs are flipped into position aroundthe endoscope distal tip as shown in FIG. 13 b.

In another embodiment of deployable LED illumination, FIG. 14 arepresents an “off” position for the LED illuminators 220 a as they arestored within the endoscope objective lens free cavity. In an “on”position, LEDs 220 b are deployed in a circular manner, rotating outsidethe objective lens cavity of the endoscope.

FIGS. 15 a and 15 b, represent anther scheme in storing 231 a LEDs intheir “off” position, next to the objective lens at the distal end 230of the endoscope. LEDs 231 a are disposed on a hinge portion 232. Thehinge portion 232 is, in turn, connected to an actuation portion 233.The LEDs 231 a are deployed into position as the actuation portion 233is pushed distally in the direction of the arrows towards the distal tipof the endoscope. Such action deploys the hinge portion 232 whichpositions the LEDs 231 b to emit light that is off-axis from the imagingoptics.

In an alternate configuration, represented in FIGS. 16 a and 16 b,another type of deployment mechanism is used. The LEDs 241 a aredisposed on hinge portion 242. The hinge portion 242 is, in turn,connected to an actuation portion 243. The LEDs 241 a are deployed intopositions by pulling the actuation portion 243 proximally in thedirection of the arrows toward the proximal end of the endoscope,deploying the LEDs 241 b into their “on” position.

FIGS. 17 a through 17 c illustrate an exemplary embodiment of LEDillumination in conjunction with a surgical tool. FIGS. 17 a and 17 bare side views of the surgical tool in an illumination “off” position.FIG. 17 c illustrates a surgical tool in an illumination or deployed“on” position, where LEDs illuminators 252 b are opened up from thestored position to illuminate the surgical work area.

In alternate embodiments of all of the endoscopes, cannulas and otherdevices described above that use LEDs for illumination, Solid StateLaser Diodes (LD) can also be used at the distal end of tools, insertiontubes, catheters, imaging scopes, cannulas, etc. Infrared Imaging coulduse IR solid state light sources to illuminate intra-vein or closetissue diagnostic and surgical procedures. IR detectors and cameras areused for thorough tissue and blood imaging along with external infraredlight sources that have appreciable penetration depth in human tissue,blood or other bodily fluids such as urine. Using a high intensity IRsource at the surgical or examination site with control over theintensity, radiation pattern, and the direction of illumination helpswith the most critical surgical procedures inside the vein, heart andother body organs.

Scanning or other directing mechanical elements could also be used toadjust the direction of illumination and control of the solid statelight sources (laser diodes, and LEDs) used in conjunction with varietyof surgical instruments inside the body, where other scanning or nonscanning image capture elements detect the light. Additionally, sincepower is provided to the solid state light source at the distal end ofthe probe or scope, resistive heat from part of the electrical signalcan also be used to reduce condensation at the probe or scope window.

By placing the illumination light sources at close proximity of theobject inside the body in diagnostic or surgical procedures, the lossesin conjunction with the transmission of light from the external sourceto the surgical site is eliminated. Thus, light sources that have equalefficiency in converting electrical power to useful light, can beoperated in much lower input power, eliminating the need forsophisticated power and heat management. Power and control signalstransmitting through appropriate wires and flex circuitry, can be easilyrouted along the tool or endoscope body to the light source.

Miniature, optical components such as lenses, mirrors, beam splitters,polarizers, waveplates, etc. can also be used in conjunction with solidstate light sources (laser diodes and LEDs), to further manipulate theillumination characteristics of the light. Lenses for example, can beused to direct the light to larger or smaller areas of the scene, orfocusing the beam to a small area on the object depending on theapplication.

Polarization characteristics of the solid state laser or polarized LEDlight output can also be used in special detection schemes, where depthperception or other biological imaging characteristics that depend onthe polarization of the light can be better perceived, similar topolarized microscopy.

The present invention may be embodied in other specific forms withoutdeparting from its spirit or essential characteristics. The describedembodiments are to be considered in all respects only as illustrativeand not restrictive. The scope of the invention is, therefore, indicatedby the appended claims rather than by the foregoing description. Allchanges which come within the meaning and range of equivalency of theclaims are to be embraced within their scope.

1. A device for insertion into a body cavity, the device comprising: a tubular portion having a proximal end and a distal end, the distal end being configured to be at least partially inserted into the body cavity; a solid state light source located on the tubular portion; and a power source electrically coupled to the solid state light source.
 2. The device of claim 1, wherein the device is any one of an endoscope tool, a cannula, a surgical tool, or a borescopy tool.
 3. The device of claim 1, wherein the solid state light source is at least one of a light emitting device (LED), laser diode (LD), ultraviolet (UV) light source, or infrared (IR) light source, or combination thereof.
 4. The device of claim 1, wherein the solid state light source is used to passively illuminate an object in the body cavity for the purpose of detecting the reflected light that is modified by the object under the illumination without affecting the object.
 5. The device of claim 1, wherein the solid state light source is to actively illuminate an object in the body cavity for the purpose of modifying the object in a specific manner.
 6. The device of claim 1, wherein the solid state light source is located near or at the proximal end of the tubular portion.
 7. The device of claim 6, wherein the tubular portion comprises at least one light guide and the solid state light source emits light into the at least one light guide.
 8. The device of claim 1, wherein the solid state light source is located between the proximal end and the distal end of the tubular portion.
 9. The device of claim 1, wherein the solid state light source is located at or near the distal end of the tubular portion.
 10. The device of claim 1, wherein the solid state light source is disposed on an extension portion that extends from the distal end of the tubular portion.
 11. The device of claim 1, wherein the solid state light source is located on an exterior surface of the tubular portion.
 12. The device of claim 1, wherein the solid state light source emits a wavelength that is at least one of a visible wavelength, UV wavelength, IR wavelength, or different color temperature white, or a combination thereof.
 13. The device of claim 1, wherein the solid state light source emits a light that is redirected or modified by at least one of a lens element, a beam splitter, a reflective cover disposed around the distal end of the tubular portion, total internal reflection in the tubular portion, a mirror, a polarizer, or a wave plate.
 14. The device of claim 1, wherein the tubular portion comprises a longitudinal axis, wherein the solid state light source can be manipulated between at least a first position wherein the solid state light source can be inserted into the body cavity, and a second position wherein the solid state light source emits a light that is non-concentric with the longitudinal axis of the tubular portion.
 15. The device in claim 1, wherein the solid state light source emits primary color illumination, further comprising a second solid state light source disposed in the tubular portion, the second solid state light source configured to emit non-primary color illumination; imaging elements disposed in the tubular portion; and a camera optically coupled to the imaging elements, wherein the primary color and non primary color illumination are used and color synchronized with the imaging elements and camera to capture true color image with wider color gamut than a primary color capture system.
 16. A device for insertion into a body cavity, the device comprising: a tubular portion having a proximal end and a distal end, the distal end being configured to be at least partially inserted into the body cavity; a solid state light source located in the tubular portion; and a power source electrically coupled to the solid state light source.
 17. The device of claim 16, further comprising at least one of detecting, imaging, or manipulating elements, or a combination thereof, disposed in the tubular portion.
 18. The device of claim 17, wherein the solid state light source is disposed in relation to the imaging elements such that light emitted from the solid state light source passes through at least a portion of the detecting, imaging, or manipulating elements.
 19. The device of claim 16, wherein the solid state light source is deployably configured such that in an insertion position, the solid state light source is contained within the tubular portion, and in a deployed position, the solid state light source is disposed exterior of the tubular portion such that optical images are able to pass through the imaging elements.
 20. A device for insertion into a body cavity, the device comprising: a tubular portion having a proximal end and a distal end, the distal end being configured to be at least partially inserted into the body cavity; a solid state light source that is deployably disposed in relation to the distal end of the tubular portion; and a power source electrically coupled to the solid state light source.
 21. The device of claim 20, further comprising a membrane having a surface and an outer edge, the outer edge or a portion of the membrane comprising a spring, the solid state light source being disposed on a surface of the membrane, the membrane being deployably disposed in relation to the distal end of the tubular portion such that in an insertion position, the membrane is in a tubular configuration and in the deployed position, the membrane is in a substantially flat configuration.
 22. The device of claim 20, wherein the tubular portion has a longitudinal axis and a longitudinal profile, further comprising a rotation portion, the solid state light source being disposed on the rotation portion, the rotation portion being deployably disposed in relation to the distal end or the body of the tubular portion such that in an insertion position, the rotation portion is within the longitudinal profile formed by the distal end or the body of the tubular portion and in the deployed position, the LEDs are positioned to emit light that is non-concentric with the longitudinal axis of the tubular portion.
 23. The device of claim 20, wherein the tubular portion has a longitudinal axis and a longitudinal profile, further comprising a hinge portion coupled to an actuation portion, the solid state light source being disposed on the hinge portion, the hinge portion being deployably disposed in relation to the distal end and the body of the tubular portion such that in an insertion position, the hinge portion is within the longitudinal profile formed by the distal end and the body of the tubular portion and in the deployed position, the LEDs are positioned to emit light that is non-concentric with the longitudinal axis of the tubular portion.
 24. The device of claim 20, further comprising at least one of detecting, imaging, or manipulating elements, or a combination thereof, disposed in the tubular portion. 